Cao Yijin

Cao Yijin (3 March 939-) was Duke of Guiyi from 14 December 942, succeeding Cao Yuande.

Biography
Cao Yijin was born in Dunhuang, Gansu, China in 939, the son of Duke Cao Yuande of Guiyi and the brother of Cao Wanyi and Cao Yi. His father died in 942, and the 3-year-old Cao Yijin inherited the duchy from him. He was guided by his regents into siding with Liang Yan during the Mongolia-Liao War, fighting against his prospective brother-in-law Liang Jing (who was betrothed to marry his sister Cao Wanyi). However, his clan was defeated by Liang Jing in the ensuing war, and Liang Jin had his brother castrated, his uncle Cao Yuanzhong and aunt Temulun executed, and eventually broke off his betrothal to Cao Wanyi, angering Cao Yijin.